> ## Documentation Index > Fetch the complete documentation index at: https://docs.honeyhive.ai/llms.txt > Use this file to discover all available pages before exploring further. # Add traces to a session (deprecated) > Deprecated. Use `POST /v1/sessions/{session_id}/events/batch` instead. This route accepts trace events under either `logs` (deprecated) or `events`. Exactly one of the two MUST be present in a request: neither → 400, both → 400. ## OpenAPI ````yaml https://raw.githubusercontent.com/honeyhiveai/honeyhive-openapi/main/openapi.yaml post /session/{session_id}/traces openapi: 3.1.0 info: title: HoneyHive Data Plane API license: name: MIT url: https://opensource.org/licenses/MIT version: 1.2.1 servers: - url: https://api.honeyhive.ai security: - BearerAuth: [] tags: - name: Charts description: > Define and manage saved charts. Charts are visualizations that aggregate metrics over time with bucketing, filters, and groupings. - name: Configurations description: > Manage prompt configurations, i.e. model parameters, message templates, and response settings that can be versioned and deployed without code changes. - name: Datapoints description: > Manage individual records inside datasets, including batch creation and mapping to source events. - name: Datasets description: > Curate collections of datapoints used as test sets for evaluations and experiments. - name: Events description: > Read and write trace events. Events are the spans that capture every step of an AI application's execution. - name: Experiments description: > Run, retrieve, and compare evaluation runs to measure how prompt or configuration changes affect agent performance. - name: Metric Versions description: > Snapshot, list, and deploy versions of a metric's definition so changes can be reviewed and rolled back without losing history. - name: Metrics description: > Define and run evaluators, i.e. automated quality checks that score traces against criteria like accuracy, safety, or correctness. - name: Queues description: > Manage annotation queues for human review of traces, turning expert feedback into labeled datasets. - name: Sessions description: > Group related trace events into sessions, the top-level container for a multi-step or multi-service AI interaction. paths: /session/{session_id}/traces: post: tags: - Sessions summary: Add traces to a session (deprecated) description: > Deprecated. Use `POST /v1/sessions/{session_id}/events/batch` instead. This route accepts trace events under either `logs` (deprecated) or `events`. Exactly one of the two MUST be present in a request: neither → 400, both → 400. operationId: addSessionTracesLegacy parameters: - name: session_id in: path required: true schema: type: string description: Session ID to add traces to requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/AddSessionTracesRequest' responses: '200': description: Traces added successfully content: application/json: schema: $ref: '#/components/schemas/SessionTracesResponse' '400': description: > Bad request: both `logs` and `events` supplied, or neither, or invalid event payload. deprecated: true components: schemas: AddSessionTracesRequest: type: object properties: logs: type: array items: $ref: '#/components/schemas/LegacyEvent' description: >- Deprecated: use `events` instead. Traces to add as raw event objects. deprecated: true events: type: array items: $ref: '#/components/schemas/LegacyEvent' description: Traces to add as raw event objects. Replaces `logs`. description: >- Request body for POST /session/{session_id}/traces (deprecated — use POST /v1/sessions/{session_id}/events/batch). Exactly one of `logs` (deprecated) or `events` must be present. deprecated: true SessionTracesResponse: type: object properties: success: type: boolean required: - success description: Response from adding traces to a session LegacyEvent: type: object properties: project: type: string deprecated: true description: >- Project name (ignored by server — project is determined from API key scope) project_id: type: string description: Project ID source: type: string description: Source of the event (e.g., sdk-python) event_name: type: string description: Name of the event event_type: type: string enum: - model - tool - chain - session description: Type of event (model, tool, chain, or session) event_id: type: string description: Unique event identifier session_id: type: string description: Session this event belongs to parent_id: type: string description: Parent event ID in the trace hierarchy children_ids: type: array items: type: string description: Child event IDs in the trace hierarchy config: type: object additionalProperties: {} description: Configuration used for this event inputs: type: object additionalProperties: {} description: Input data for the event outputs: type: object additionalProperties: {} description: Output data from the event error: type: - string - 'null' description: Error message if the event failed start_time: type: number description: Event start time as Unix milliseconds end_time: type: number description: Event end time as Unix milliseconds duration: type: number description: Event duration in milliseconds metadata: type: object additionalProperties: {} description: Arbitrary metadata for the event feedback: type: object additionalProperties: {} description: Feedback data associated with the event metrics: type: object additionalProperties: {} description: Metric values computed for the event user_properties: type: object additionalProperties: {} description: User properties associated with the event additionalProperties: {} description: Full event object for legacy event creation endpoints securitySchemes: BearerAuth: type: http scheme: bearer ````